Airborne organic compounds in the Canadian Arctic and development of a collection method for organochlorines in air.

摘要

Many organochlorine pollutants have saturation vapor pressures between 10{dollar}sp{lcub}-8{rcub}{dollar} to 10{dollar}sp0{dollar} torr and exist in the atmosphere as vapors and/or associated with airborne particles. Collection methods are needed for the organic pollutants having vapor pressures between 10{dollar}sp{lcub}-3{rcub}{dollar} and 10{dollar}sp0{dollar} torr because they are too volatile to be retained by high-volume collection methods using polyurethane foam (PUF) and are usually present in ambient air at levels below the detection limit of low-volume samplers. A commercial high volume air sampler was evaluated for the collection of di- through hexachlorobenzene (HCB), hexachlorocyclohexanes (HCH), and di- through pentachlorophenol using granular solid adsorbents (Tenax-GC, XAD-2, or Florisil) sandwiched between two PUF plugs. Vapors of these compounds were diluted in a flowing stream of up to 380 m{dollar}sp3{dollar} of filtered and scrubbed laboratory air and then pulled through front and back PUF-granular adsorbent traps. All three adsorbents are suitable for the collection of tetrachlorobenzene--HCB and HCH, and Tenax-GC is suitable for the collection di-tetrachlorophenol. The method was applied to the collection of these compounds from ambient air.; The high Arctic is one of the most remote and isolated areas in the world. Despite the region's seemingly pristine character, Arctic ecosystems are exposed to anthropogenic pollutants from temperate latitudes. Long range atmospheric transport is considered to be a major pathway of organochlorine pesticides to the Arctic, polychlorinated biphenyls (PCB), and polycyclic aromatic hydrocarbons (PAH). High volume air samples were collected using a filter-PUF adsorbent train on a floating ice island (81{dollar}spcirc{dollar} N, 100{dollar}spcirc{dollar} W) during August-September 1986 and June 1987 and at Alert, Canada (82.5{dollar}spcirc{dollar} N, 62.3{dollar}spcirc{dollar} W) during February-April 1988. Samples were analyzed by gas chromatography using electron capture detection and by gas chromatography--mass spectrometry in the negative ion and electron impact modes. Compounds quantified for all trips included HCHs, HCB, polychlorinated camphenes, chlordane, PCB, and DDT compounds. Compounds quantified for the Alert trip also included pentachlorobenzene, biphenyl, dibenzofuran, and 3-6 ring PAH. The partitioning of these compounds between gas-phase and particle-phase is described for the Alert samples.